Crossbows conventionally include an elongated barrel of wood, metal or composite composition that essentially forms a mounting base for the remainder of the crossbow hardware. A pair of resilient limbs of wood or composite composition project in opposite directions from one end of the barrel, with the free ends of the limbs being joined by a bowstring cable. A support is provided on the upper surface of the barrel for holding a bolt. A trigger mechanism is carried by the barrel for engaging and holding the bowstring cable in the drawn or cocked position, and for selectively releasing the cable so as to propel the bolt from the bow.
It is a general object of the present invention to provide an improved trigger mechanism that is characterized by a long power strike, improved balance and a reduced number of component parts, which in turn reduces manufacturing and repair costs, that obtains smooth trigger action as the bowstring cable is both latched, that exhibits no change in pressure as the trigger is squeezed and the bolt is released, that includes a dry-fire safety feature to prevent release of the bowstring cable if there is no bolt in the bow, and/or that includes an operator safety for selectively preventing firing of the bow. It is another object of the present invention to provide a crossbow in which the trigger and safety are disposed and configured in a manner analogous to conventional rifles.
The trigger mechanism in accordance with the presently preferred embodiment of the invention includes a latch mounted on the barrel for pivoting between a closed position in which the latch captures the bowstring cable in the drawn position, and an open position for releasing the cable against flexure of the limbs. A latch release is mounted adjacent to and in opposed engagement with the latch for engaging the latch releasably to hold the latch in both the open and closed positions. A trigger linkage operatively couples a trigger to the latch release, and is responsive to movement of the trigger by an operator to release the latch release from holding the latch in the closed position, such that the force of the bowstring cable against the latch pivots the latch and the latch release from the closed to the open positions of these components so as to release the cable.
A dry-fire safety is carried as part of the trigger mechanism for engaging the bowstring cable so as to prevent release of the bowstring cable when a bolt is absent from the bolt support on the stock in engagement with the cable. The dry-fire safety in the preferred embodiment of the invention comprises a spring-biased safety latch disposed in opposition to the bolt support on the stock immediately adjacent to the cable latch. Placement of a bolt on the bolt support in engagement with a drawn cable biases the safety latch upwardly against the safety latch spring so as to permit passage of the bowstring cable and the bolt when the trigger is released. In the absence of a bolt on the bolt support, the safety latch blocks passage of the bowstring cable when the trigger mechanism is released.
In the preferred embodiment of the invention, the cable latch, the latch release and the dry-fire safety are carried within a trigger housing that is mounted on the barrel. The trigger linkage mechanism extends into the housing, and terminates within the housing in a sear pin in engagement with the latch release. The opposing end of the trigger linkage is disposed adjacent to an operator safety slide carried by the barrel. A pin on the trigger linkage is biased by a spring into engagement with channels in the safety slide for resiliently holding the safety slide in blocking and releasing positions of the safety slide. A land on the safety slide is disposed either opposed to or spaced from the end of the trigger linkage for either blocking movement of the trigger linkage and release of the bowstring cable, or permitting movement of the trigger linkage and release of the bowstring cable, depending upon position of the safety slide.